1. Field of the Invention
The present invention relates to a semiconductor device, and more particularly, to an apparatus for cooling a semiconductor package.
2. Description of the Related Art
A central processing unit (hereinafter, referred to as xe2x80x9cCPUxe2x80x9d) currently manufactured operates at speeds of greater than 500 MHz. With this increase in speed, power consumption increases. Meanwhile, increases in temperature at a chip junction part of the CPU may lead to a decrease in operation frequency. Consequently, it is necessary to maintain the junction temperature below a predetermined temperature to ensure reliability of the CPU.
To dissipate heat generated at a chip junction part in a semiconductor package to the air more effectively, a semiconductor package, on which a CPU chip is mounted, uses a ceramic substrate having more excellent heat properties than the existing plastic package. Also, a heat sink and a fan may be attached to more effectively dissipate heat in the semiconductor package outward. When operation frequency increases, electrical power consumption increases proportionally. Consequently, a larger or more efficient heat sink is required in order to use a device operating at high frequencies.
FIG. 1 is a cross-sectional view illustrating a conventional apparatus for cooling a semiconductor package, to which a heat sink and a fan are attached.
Referring to FIG. 1, a conventional heat sink 21, which is mounted over a semiconductor package 15, has a plurality of equal length, parallel fins 20. Heat generated from a semiconductor package body 14 is mostly transmitted to the heat sink 21 and a board (not shown) over which the semiconductor package 15 is mounted and particularly, the heat transmitted to the heat sink 21 is emitted outward by a convection current effect created by a fan 26. However, airflow is stagnant and heat is concentrated at the central part of the heat sink 21 due to a motor 22 at the center of the fan 26. Consequently, the convection current effect at the central part of the heat sink 21 decreases significantly. Moreover, a plurality of equal length, parallel fins 20 in the heat sink are formed at both a central part and a peripheral part of the heat sink 21. Therefore, the convention current effect thereof further decreases, and heat is further concentrated at the central part of the heat sink 21. Namely, the heat generated from the semiconductor package body 14 is ineffectively cooled.
To solve the above problems, it is an object of the present invention to provide an apparatus for cooling a semiconductor package capable of effectively cooling or dissipating heat generated from a semiconductor package body.
Accordingly, to achieve the above object, there is provided an apparatus for cooling a semiconductor package, including a heat sink mounted over a semiconductor package for dissipating heat and a fan installed over the heat sink, wherein the heat sink includes a base plate, a support bar installed over the base plate for supporting the fan, a plurality of parallel fins, whose lengths are shorter toward the central part of the heat sink, extending from the base plate and air guide plates for guiding the flow of air in the heat sink to the central part thereof.
The air guide plates are formed to be slanted along the fins, whose lengths get shorter from the peripheral part to the central part of the heat sink.
The air guide plates may be parallel and face each other so that air flows in a horizontal direction. Also, the air guide plates may be adjacent to each other crossing in a vertical direction and a horizontal direction so that air flows in a diagonal direction.
It is preferable that the central part of the heat sink comprises fins of the same length.
It is preferable that the fins are formed rectangularly to have a checkerboard form.
A motor is installed at the central part of the fan, and blades serving as a passage for the inflow and outflow of air are at the peripheral part of the fan. The fan may be attached to and detached from the heat sink.